Railway truck with releasable bearing adapter

ABSTRACT

An adapter assembly of a vehicle includes a bearing adapter configured to physically contact a bearing on an axle of the vehicle, and an adapter pad nested within an opening of a side frame of the vehicle and secured to at least one thrust lug of the side frame. The adapter pad includes a base section and legs depending from the base section. The legs are compressed between the at least one thrust lug of the side frame and shoulders of the bearing adapter to exert frictional forces on the shoulders of the bearing adapter. A combination of the frictional forces exerted by the adapter pad on the bearing adapter is less than a weight of the bearing adapter, such that as the side frame rises away from the bearing during movement of the vehicle, the adapter pad rises relative to the bearing adapter.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application relates to and claims priority benefits from U.S.Provisional Patent Application No. 63/162,396, filed Mar. 17, 2021,which is hereby incorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

Embodiments of the present disclosure generally relate to truckassemblies for rail vehicles, such as rail cars, and, more particularly,to truck assemblies that include one or more releasable bearingadapters, which are configured to mechanically connect a side frame ofthe truck assembly to a bearing on a wheel-mounted axle.

BACKGROUND OF THE DISCLOSURE

Rail vehicles travel along railways, which have tracks that includerails. A rail vehicle includes one or more truck assemblies that supportone or more car bodies. Each truck assembly includes two side frames, abolster, and at least two wheelsets. The bolster extends laterallybetween and is supported on each side frame. Each wheelset includes anaxle, two wheels, and two bearings (e.g., roller bearings). The wheelsmay be press fit on the axle, and the bearings may be secured at theends of the axle. Each bearing is connected to one of the side framesvia an adapter assembly. The adapter assembly includes a bearing adapterthat has an arcuate opening contoured to accommodate the bearing. Theadapter assembly also includes an adapter pad that nests into an uppercavity of the bearing adapter. The adapter assembly nests into apedestal jaw opening at the longitudinal end of each side frame. Theadapter assembly is disposed between the bearing and the pedestal jaw.More specifically, the adapter pad is positioned between the bearingadapter and the surfaces of the pedestal jaw that define the opening.The bearing adapter is positioned between the adapter pad and thebearing. The adapter pad is at least partially compressed between thebearing adapter and the surfaces of the pedestal jaw, and the frictionalforces at the interfaces between the components secure the bearingadapter in place relative to the side frame.

During travel of the railway freight car, the truck experiences variousvertical and lateral forces exerted on the truck via the rails, thespring groups, and inertia. It is possible for the side frame toexperience vertical forces that lift or raise the side frame, at leasttemporarily, relative to the wheelsets in contact with the rails. If theadapter assembly is properly installed, the lifting of the side framerelative to the wheelsets is not a concern due to the weight of thefreight car. However, if the adapter assembly is not properly installed,the bearing adapter may at least partially separate from the surface ofthe bearing, causing the bearing adapter and the bearing to becomedisplaced. The displacement may cause uneven and/or excessive wear onthe components, which could reduce the operational lifespan of thecomponents.

SUMMARY OF THE DISCLOSURE

A need exists for a railway truck that reduces the likelihood of anincorrectly-installed bearing adapter becoming dislodged or displacedrelative to the bearing on the axle during travel of the railway freightcar.

With those needs in mind, certain embodiments of the present disclosureprovide an adapter assembly of a vehicle. The adapter assembly includesa bearing adapter configured to physically contact a bearing on an axleof the vehicle, and an adapter pad nested within an opening of a sideframe of the vehicle and secured to at least one thrust lug of the sideframe. The adapter pad includes a base section and legs depending fromthe base section. The legs are compressed between the at least onethrust lug of the side frame and shoulders of the bearing adapter toexert frictional forces on the shoulders of the bearing adapter. Acombination of the frictional forces exerted by the adapter pad on thebearing adapter is less than a weight of the bearing adapter, such thatas the side frame rises away from the bearing during movement of thevehicle, the adapter pad is configured to rise relative to the bearingadapter.

Certain embodiments of the present disclosure provide a truck assemblyof a rail vehicle. The truck assembly includes a side frame thatcomprises at least one thrust lug, an axle that comprises a bearing, andan adapter assembly that comprises an adapter pad and a bearing adapter.The adapter pad is nested within an opening of the side frame andsecured to the at least one thrust lug via an interference fit. Theadapter pad includes a base section and legs depending from the basesection. The bearing adapter includes multiple shoulders and isconfigured to physically contact the bearing. The legs of the adapterpad are compressed between the at least one thrust lug of the side frameand the shoulders of the bearing adapter. The legs include ribs thatexert frictional forces on the shoulders. A combination of thefrictional forces provided by the ribs is less than a weight of thebearing adapter such that, as the side frame rises away from the bearingduring movement of the rail vehicle, the adapter pad is configured torise relative to the bearing adapter.

Certain embodiments of the present disclosure provide a method forforming a truck assembly of a rail vehicle. The method includesinstalling an adapter pad within an opening of a side frame such thatthe adapter pad secures to at least one thrust lug of the side frame viaan interference fit. The adapter pad includes a base section and legsdepending from the base section. The method includes loading a bearingadapter into the opening such that the legs of the adapter pad arecompressed by the shoulders of the bearing adapter. The method alsoincludes coupling the side frame to an axle such that an arcuate loweredge of the bearing adapter physically contacts a bearing on the axle.The legs exert frictional forces on the shoulders of the bearingadapter, and a combination of the frictional forces provided by the legsis less than a weight of the bearing adapter such that the bearingadapter lowers relative to the adapter pad, due to the weight, as theside frame rises away from the bearing during movement of the railvehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a portion of a railway truckaccording to an embodiment.

FIG. 2 is a top view of a bearing adapter according to an embodiment.

FIG. 3 is an end view of the bearing adapter shown in FIG. 2.

FIG. 4 is a side elevation view of the bearing adapter shown in FIGS. 2and 3.

FIG. 5 is a top perspective view of an adapter pad according to anembodiment.

FIG. 6 is a bottom perspective view of the adapter pad shown in FIG. 5.

FIG. 7 is a top plan view of the adapter pad shown in FIGS. 5 and 6.

FIG. 8 is an end view of the adapter pad shown in FIGS. 5 through 7.

FIG. 9 is a side elevation view of the adapter pad shown in FIGS. 5through 8.

FIG. 10 is a perspective view of a portion of the railway freight cartruck showing the adapter assembly in contact with a bearing at the endof an axle of a wheelset according to an embodiment.

FIG. 11 is a schematic diagram of the adapter assembly installed in therailway truck showing forces applied on the bearing adapter in a restposition according to an embodiment.

FIG. 12 is a schematic diagram of the adapter assembly installed in therailway truck showing forces applied on the bearing adapter in a raisedposition according to an embodiment.

FIG. 13 is another schematic diagram of the adapter assembly showingforces applied on the bearing adapter in the raised position.

FIG. 14 shows a top view, an end view, and a side view of the adapterpad with marked dimensions according to a specific non-limiting example.

FIG. 15 illustrates a flow chart of a method of forming a truck assemblyof a rail vehicle, according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

The foregoing summary, as well as the following detailed description ofcertain embodiments, will be better understood when read in conjunctionwith the appended drawings. As used herein, an element or step recitedin the singular and preceded by the word “a” or “an” should beunderstood as not necessarily excluding the plural of the elements orsteps. Further, references to “one embodiment” are not intended to beinterpreted as excluding the existence of additional embodiments thatalso incorporate the recited features. Moreover, unless explicitlystated to the contrary, embodiments “comprising” or “having” an elementor a plurality of elements having a particular condition may includeadditional elements not having that condition.

Certain embodiments of the present disclosure provide an adapterassembly that is held between a bearing on an axle and a side frame of atruck assembly. The adapter assembly includes a metal bearing adapterthat engages (e.g., in physical contact) the surface of the bearing. Theadapter assembly also includes an elastomeric adapter pad that is heldbetween the metal bearing adapter and a pedestal jaw of the side frame.The adapter pad is retained within a pedestal jaw opening via aninterference (or friction) fit. The adapter pad couples to the bearingadapter via an interference fit as well. The present applicationdescribes technology that could alleviate concerns of adapter assemblydisplacement when the side frame rises relative to the bearing, even ifinstallation of the adapter assembly by the end user is not donecorrectly.

In one or more embodiments, the adapter assembly is designed to enablethe metal bearing adapter to release from the adapter pad under its ownweight in the event that the side frame lifts or rises relative to thebearing and the axle. For example, when the side frame lifts away fromthe bearing, the adapter pad at least partially uncouples from the metalbearing adapter. The adapter pad retains its position within thepedestal jaw opening of the side frame and moves with the side frame.The metal bearing adapter drops relative to the adapter pad and retainsits mechanical connection to the bearing. Once the side frame lowersagain, due to gravity, the adapter pad and the bearing adapter movetowards each other and reestablish the interference fit that was presentprior to the side frame lifting event. For example, the adapter assemblyreestablishes the correct positioning of the adapter pad and the bearingadapter relative to each other and relative to the components thatengage the adapter pad and the bearing adapter.

The adapter pad is specifically formulated such that the total amount offrictional force applied on the bearing adapter is less than the weightof the bearing adapter. The bearing assists with supporting the weightof the bearing adapter in a rest position. The rest position representsthe state at which weight of the side frame is supported by the bearingon the axle. The truck may be in the rest position for the vast majorityof time, only deviating from the rest position when the side frametemporarily lifts away from the bearing during movement of the vehicle.Once the side frame experiences lift such that the normal force providedby the bearing on the metal bearing adapter is reduced or totallyremoved, the weight of the bearing adapter overcomes the frictionalretention provided by the adapter pad. As a result, the metal bearingadapter slides downward relative to the adapter pad. By releasing fromthe coupled position with the adapter pad, the metal bearing adapter canretain the desired fit and position on the bearing. The bearing adapteravoids becoming dislodged or displaced relative to the bearing, whichcould cause accelerated wear and other issues. By staying in place onthe bearing, there is little or no risk of the side frame and thebearing adapter being displaced in the event of an applied lateralforce. Stated differently, the adapter pad is configured to grip thebearing adapter and hold the bearing adapter in place longitudinally andlaterally, but the frictional grip force is insufficient to support theweight of the bearing adapter. When the side frame lifts, the weight ofthe bearing adaptor enables the bearing adapter to lower verticallyrelative to the adapter pad and the side frame to maintain physicalcontact with the bearing.

The adapter pad can be formulated to provide a specific amount offrictional force by selecting specific materials with desirablematerials properties (e.g., hardness, stiffness, friction coefficient,compressibility, etc.) and specifying the size and thickness of theadapter pad features. The properties of the adapter pad are selectedbased on the weight of the bearing adapter. For example, the adapter padmay be designed to provide less frictional force against a lighterbearing adapter and to provide more frictional force against a heavierbearing adapter. Optionally, the weight of the bearing adapter may beselected based on existing properties of the adapter pad, such as theamount of frictional force supplied by the adapter pad. The bearingadapter may be composed of one or more metals. The specific type(s) ofmetal used in the bearing adapter may be selected based on a desiredweight of the bearing adapter to accomplish the drop function describedherein.

FIG. 1 is an exploded perspective view of a portion of a railway freightcar truck 10 according to an embodiment. The railway truck includes abolster 12 and two side frames 14, although a segment of only one sideframe 14 is visible in the illustrated portion of the railway truck 10.The railway truck also includes an adapter assembly 59 that includes abearing adapter 30 and an adapter pad 32.

The bolster 12 extends laterally between the two side frames 14 andconnects to both side frames 14. The bolster 12 and the side frames 14may be unitary cast steel structures. Side frames 14 extendlongitudinally and parallel with the railway tracks. As used herein,references to “longitudinal” refer to directions that are generallyparallel to the rails and the direction of travel of the railwayvehicle, and references to “lateral” refer to directions that aregenerally orthogonal to the rails and the direction of travel of therailway vehicle. Each side frame 14 includes a bolster opening 18through which one end 16 of the bolster 12 extends. The end 16 of thebolster 12 is supported on a spring group 20, with damping devices knownas friction shoes.

The longitudinal end of each side frame 14 includes a downwardlyextending pedestal jaw 22. The pedestal jaw 22 includes a pedestal jawopening 23 that is defined by an inner wall 24 of the pedestal jaw 22, aceiling section 28 of the pedestal jaw 22, and an outer wall 26 of thepedestal jaw 22 that faces towards the inner wall 24. At the interfacebetween the inner wall 24 and the ceiling section 28, there is an innerthrust lug 29. Inner thrust lug 29 has an angled section that extendsfrom an upper section of the inner wall 24 to an inward section ofceiling section 28. Similarly, but not entirely seen in this perspectiveview of FIG. 1, outer thrust lug 31 is located at the interface betweenthe outer wall 26 and the ceiling section 28. The outer thrust lug 31includes an angled section extending from an upper section of the outerwall 26 extending to an inward section of the ceiling section 28.

The bearing adapter 30 has a generally rectangular structure with fourdepending shoulders 43, 44, 45, 46 extending therefrom. Three of theshoulders 44, 45, 46 are visible in FIG. 1, the fourth shoulder 43 isshown in FIG. 2. In at least one embodiment, the bearing adapter 30 ismetallic, such that it is composed of one or more metals. In anon-limiting example, the bearing adapter 30 is composed of steel. Thebearing adapter 30 has a unitary, monolithic (e.g., one-piece) body. Thebearing adapter 30 may be formed via casting or the like.

The bearing adapter 30 in an embodiment has a rectangular top section36, which is seen to be generally flat (e.g., planar). Two raised edgesupports 38 upwardly extend from one lateral edge of the bearing adapter30, and two raised edge supports 40 upwardly extend from the oppositelateral edge of the bearing adapter 30. The raised edge supports 38, 40form a pocket or cavity for receiving the adapter pad 32, enabling theadapter pad 32 to nest along the upper or top side of the adapter 30.The lower or bottom side of the bearing adapter 30 has an arcuate recessalong each lower lateral edge, which together define an arcuate opening42 for receiving and accommodating the convex surface of the bearing.For example, the arcuate opening 42 is adapted to seat against thebearing, as shown in FIG. 10.

The depending shoulders are spaced apart from one another. For example,two shoulders 44, 46 are disposed at one longitudinal end of the adapter30 and are laterally spaced apart from each other. The shoulders 44, 46define a gap 47 therebetween. The gap 47 is sized and shaped to receivelegs of the adapter pad 32, as described herein. The third shoulder 45and the fourth shoulder, which is not visible, are located at theopposite longitudinal end from the shoulders 44, 46. The third andfourth shoulders are spaced apart from each other similar to the firstand second shoulders 44, 46, such that another gap is defined to receivelegs of the adapter pad 32.

FIGS. 2 through 4 show the bearing adapter 30 according to theembodiment shown in FIG. 1. FIG. 2 is a top view of a bearing adapter;FIG. 3 is an end view of the bearing adapter; and FIG. 4 is a sideelevation view of the bearing adapter. In an embodiment, the bearingadapter 30 defines depressions 48 and 49 along the upper surface of thetop section 36. The depressions 48, 49 in the illustrated embodiment aregrooves that are each laterally elongated across the top section 36. Thedepression 48 is longitudinally spaced apart from the depression 49. Thedepressions 48 and 49 may extend across the top section 36 from anintermediate support 60 to another intermediate support 62. Theintermediate supports 60 and 62 are disposed between the top section 36and the raised edge supports 38, 40, respectively, and longitudinallyextend. The depressions 48, 49 are sized, shaped, and positioned toreceive tabs or protrusions 64, 66 (shown in FIG. 9) of the adapter pad32 to provide lateral and longitudinal stability for the adapter pad 32when fit against the bearing adapter 30.

Referring back to FIG. 1, the adapter pad 32 has a generally rectangularstructure with four depending legs 54, 55, 56, 57 extending therefrom.Three of the legs 54, 55, 56 are visible in FIG. 1, and fourth leg 57 isshown in FIGS. 5 and 6. In at least one embodiment, the adapter pad 32is elastomeric, such that it is composed of one or more polymers orcopolymers, natural rubber, synthetic rubber, elastomers, silicone,and/or the like. The adapter pad 32 is at least partially compressive toprovide an interference fit for coupling the adapter pad 32 to thethrust lugs 29, 31 of the side frame. The composition of the adapter pad32 may be selected to achieve a specific durometer hardness in order toprovide the compressive properties as well as strength for durability.In a non-limiting example, the adapter pad 32 has a durometer hardnessin a range from 90A to 58D. The adapter pad 32 has a unitary, monolithic(e.g., one-piece) body, and may be formed via a molding process, such asinjection molding, casting, or the like. Casting the adapter pad 32 maybe preferred over injection molding to obtain the desired hardnessratings, but other forming operations are possible so long as thepreferred hardness ratings of adapter pad 32 are provided.

Additional reference is made to FIGS. 5 through 9, which show theadapter pad 32 of FIG. 1 in more detail. FIG. 5 is a top perspectiveview of the adapter pad. FIG. 6 is a bottom perspective view of theadapter pad. FIG. 7 is a top plan view of the adapter pad. FIG. 8 is anend view of the adapter pad. FIG. 9 is a side elevation view of theadapter pad.

The adapter pad 32 has a generally rectangular and flat (e.g., planar)base section 50. The adapter pad 32 extends from lateral edge 52 to anopposite lateral edge 53 (shown in FIG. 5). The four depending legs 54,55, 56, 57 extend downwardly relative to the base section 50. The legs54, 56 are disposed at one longitudinal end of the adapter pad 32, andthe legs 55, 57 are disposed at the other longitudinal end. The legs arespaced apart from one another. For example, the legs 54, 56 arelaterally spaced apart to define a thrust lug cavity 58 therebetween.The thrust lug cavity 58 is sized and shaped to receive and accommodateone of the thrust lugs 29, 31 of the side frame therein. A lateral widthof the thrust lug cavity 58 may be the same size or slightly smallerthan the lateral width of the thrust lugs 29, 31 to ensure that the legs54, 56 grip and at least slightly squeeze the sides of the thrust lugthat is received in the cavity to provide a friction or interferencefit. A similar thrust lug cavity 58 is formed on the other longitudinalend of adapter pad 32 between the legs 55, 57 for receiving the otherthrust lug 29, 31 therein. The legs 54, 55 are disposed along the firstlateral edge 52, and the legs 56, 57 are disposed along the secondlateral edge 53.

The adapter pad 32 optionally includes depending protrusions 64, 66 thatextend downwardly from a bottom surface 72 of the base section 50, asshown in FIG. 9. The protrusions 64, 66 may extend laterally across thewidth of adapter pad 32, extending to, or nearly to, the lateral edges52, 53. The protrusions 64, 66 are designed to be fit into thedepressions 48, 49, respectively, in the top section 36 of the bearingadapter 30. Such fitting provides longitudinal stability for the adapterpad 32 when nested into the cavity defined along the top of the bearingadapter 30. Lateral stability is provided by the edges 52, 53 of theadapter pad 32 abutting the raised edge supports 38, 40, respectively,of the bearing adapter 30.

As shown in FIGS. 5, 6, and 8, the adapter pad 32 includes ribs thatproject outward from side walls of the adapter pad 32. In theillustrated embodiment, the ribs include exterior ribs 80 and interiorribs 82. The ribs 80, 82 are provided to apply frictional forces againstthe contacting surfaces of the adapter 30 and the thrust lugs 29, 31 forcoupling the adapter assembly 59 to the side frame 14 via aninterference fit. For example, the ribs 80, 82 may compress and deformwhen compressed against the thrust lugs 29, 31 and the shoulders 43-46of the adapter 30. The compressive forces cause the ribs 80, 82 toresiliently exert a pressing force against the thrust lugs 29, 31 andthe shoulders 43, 46, which increases the friction at the interface.

The exterior ribs 80 engage the bearing adapter 30, and morespecifically the shoulders 43, 44, 45, 46 of the adapter 30. In theillustrated embodiment, the exterior ribs 80 are disposed alonglaterally-facing outer surfaces 84 of each of legs 54, 55, 56, 57. Theexterior ribs 80 are longitudinally elongated. The interior ribs 82engage the thrust lugs 29, 31 of the pedestal jaw 22 of the side frame14. The interior ribs 82 include a longitudinally-elongated interiorribs 82 a that are disposed along laterally-facing inner surfaces 85 ofeach of the legs 54-57. The interior rib 82 a of each leg 54-57 may bealigned with the exterior rib 80 in a vertical direction, as shown inFIG. 8, such that the two ribs 82 a, 80 are mirror images along oppositesides of the respective leg. The interior ribs 82 may also includelaterally-elongated ribs 82 b disposed along respective longitudinal endwalls 86 of the base section 50. The ribs 82 b connect to and extendbetween the ribs 82 a.

FIG. 10 is a perspective view of a portion of the railway freight cartruck 10 showing the adapter assembly 59 in contact with a bearing 60 atthe end of an axle 62 of a wheelset 64 according to an embodiment. Toassemble the adapter pad 32 onto the top of the bearing adapter 30, theadapter pad 32 nests into the pocket defined along the top of theadapter 30 laterally between the raised edge supports 38, 40. The legs54, 56 of the adapter pad 32 project downwardly into the gap 47 betweenthe shoulders 44, 46 of the adapter 30. The legs 54, 56 are supportedlaterally against the shoulders 44, 46. The exterior ribs 80 on the legs54, 56 physically engage and press against inner surfaces of thecorresponding shoulders 44, 46 to provide an interference fit betweenthe adapter pad 32 and the bearing adapter 30.

The bearing 60 fits into the arcuate opening 42 of the bearing adapter30. A rolling or rotating surface 73 of the bearing 60 physicallycontacts lower edges 74 of the bearing adapter 30 that define thearcuate opening 42. The bearing 60 rotates relative to the adapter 30while retaining physical contact at the interface between the twocomponents.

With additional reference to FIG. 1, the adapter assembly 59 isassembled to the side frame 14 by loading the adapter assembly 59 intothe pedestal jaw opening 23. For example, the adapter pad 32 is pressedupward and a top surface 70 of the base section 50 may physically engage(e.g., abut) the ceiling section 28 of the pedestal jaw 22, and thethrust lugs 29, 31 are received into the corresponding thrust lugcavities 58 of the adapter pad 32. The interior ribs 82 a, 82 bphysically engage and press against corresponding surfaces of the thrustlugs 29, 31 to provide an interference fit between the adapter pad 32and the side frame 14. For example, the two longitudinal ribs 82 a andthe lateral rib 82 b that extend into a common thrust lug cavity 58engage three different surfaces of the corresponding thrust lug 29, 31.

When the adapter assembly 59 is installed in the pedestal jaw opening 23and the bearing 60 is fit into the arcuate opening 42 of the bearingadapter 30, the legs 54-57 of the adapter pad 32, or at least the ribs80, 82 a thereon, are laterally compressed between the thrust lugs 29,31 and the shoulders 43-46 of the bearing adapter 30. The two lateralribs 82 b are longitudinally compressed between respective verticalfaces of the two thrust lugs 29, 31. For example, each rib 82 b iscompressed between a vertical face of the thrust lug 29, 31 and an endwall of the bearing adapter 30 (disposed between two shoulders thereof.

FIG. 11 is a schematic diagram of the adapter assembly 59 installed inthe railway truck showing forces applied on the bearing adapter 30 in arest position according to an embodiment. The components shown in thediagram are simplified illustrations, and may not represent the actualshapes and sizes shown in detail in FIGS. 1 through 10. In the restposition, the bearing adapter 30 is coupled to the adapter pad 32 via aninterference fit. For example, the legs 54, 56, including the ribs 80,82 a thereon, are compressed between the sides of the thrust lug 29 andthe shoulders 44, 46 of the bearing adapter 30. The ribs 80 exertfrictional forces (F_(f1), F_(f2)) on the inner surfaces of theshoulders 44, 46, which support the weight of the bearing adapter 30. Asdescribed above, the adapter pad 32 is specifically formulated such thatthe total or combined frictional forces exerted on the bearing adapter30 are less than the weight of the adapter 30. In the rest position, thebearing 60 supports the rest of the weight of the adapter 30 by exertinga normal force (F_(N)) on the arcuate lower edges 74 (shown in FIG. 10).In FIG. 11, the combined forces between the frictional forces exerted bythe pad 32 and the normal force exerted by the bearing 60 support theweight (F_(w)) of the bearing adapter 30 (e.g.,F_(f1,f2, fn)+F_(N)=F_(w)).

FIG. 12 is a schematic diagram of the adapter assembly 59 installed inthe railway truck showing forces applied on the bearing adapter 30 in araised position according to an embodiment. In the raised position, theside frame lifts relative to the wheelset. As shown in FIG. 12, thebearing 60 moves downward away from the thrust lug 29 (and/or the thrustlug 29 moves upward away from the bearing 60). The adapter pad 32 iscoupled to the thrust lug 29 (and the side frame in general) via theinterference fit provided by the interior ribs 82 a, 82 b, so theadapter pad 32 moves with the thrust lug 29. In the raised position, thebearing 60 significantly reduces if not entirely ceases to support theweight of the adapter 30. In FIG. 12, the bearing is shown astemporarily separating from the adapter 30 to indicate that there is nonormal force applied on the adapter 30 from below. In operation, theremay not be any physical separation between the adapter 30 and thebearing 60, even temporarily. The weight of the adapter 30 and thefrictional forces exerted on the adapter 30 are the same in FIG. 12 asdescribed in FIG. 11, but without the support by the bearing 60 theweight of the adapter 30 exceeds the forces maintaining the positioningof the bearing adapter 30 relative to the adapter pad 32 (e.g.,F_(w)>F_(f1,f2, fn)).

FIG. 13 shows the result of the unbalanced forces in FIG. 12. Becausethe weight (e.g., force due to gravity) of the bearing adapter 30exceeds the frictional forces, the adapter 30 drops to maintain contactwith the surface of the bearing 60. This result is favorable as itmaintains the desired fit and coupling between the bearing adapter 30and the bearing 60. The bearing 60 is able to support the entire weight,if necessary, of the adapter 30. As shown in FIG. 13, the interferencefit between the adapter pad 32 and the thrust lugs 29, 31 of the sideframe is sufficient to support the weight of the adapter pad 32 toretain the adapter pad 32 in the fixed position relative to the sideframe. For example, the combined frictional forces provided by theinterior ribs 82 a, 82 b along the thrust lugs is equal to the weight ofthe adapter pad 32, such that the adapter pad 32 does not drop.

Typically the drop distance of the bearing adapter 30 is relativelyshort, such as no greater than 1 inch or even no greater than 0.5 inch.Although FIG. 13 shows the adapter 30 separated from the adapter pad 32and the ribs 80 thereof, it is expected that typically the ribs 80 willmaintain engagement with the shoulders 44, 46 even in the lowered ordropped position of the bearing adapter 30, such that the pad 32continuously applies a frictional force on the adapter 30. Once the sideframe lowers relative to the wheelset, the assembly returns to the restposition shown in FIG. 11.

FIG. 14 shows a top view, an end view, and a side view of the adapterpad 32 with marked dimensions according to a specific non-limitingexample. As shown in FIG. 14, the lateral width of the adapter pad 32 is4.81 inches without factoring the ribs 80, and is 4.91 inches with theribs 80. The ribs 80 are designed to be relatively small, and mayproject less than 0.08 inches from the surrounding surface of the legs.In this case, each rib 80 protrudes only 0.05 inches beyond the surface.The amplitude of the ribs 80 adds only 0.1 inches to the width, whichrepresents only 2% of the total width.

FIG. 15 illustrates a flow chart 100 of a method of forming a truckassembly of a rail vehicle, according to an embodiment of the presentdisclosure. The method includes, at 102, installing an adapter padwithin a pedestal jaw opening of a side frame such that the adapter padsecures to at least one thrust lug of the side frame via an interferencefit. The adapter pad comprises a base section and legs depending fromthe base section. At 104, a bearing adapter is loaded into the pedestaljaw opening such that each of the legs is compressed between acorresponding thrust lug of the side frame and a different correspondingshoulder of the bearing adapter. The method also includes, at 106,coupling the side frame to an axle such that an arcuate lower edge ofthe bearing adapter physically contacts a bearing on the axle. The legsinclude ribs that exert frictional forces on the shoulders of thebearing adapter when the adapter assembly is in a rest position. Acombination of the frictional forces provided by the ribs is less than aweight of the bearing adapter such that the bearing adapter lowersrelative to the adapter pad due to its weight in response to the sideframe rising relative to the bearing.

While various spatial and directional terms, such as top, bottom, lower,mid, lateral, horizontal, vertical, front and the like may be used todescribe embodiments of the present disclosure, it is understood thatsuch terms are merely used with respect to the orientations shown in thedrawings. The orientations may be inverted, rotated, or otherwisechanged, such that an upper portion is a lower portion, and vice versa,horizontal becomes vertical, and the like.

As used herein, a structure, limitation, or element that is “configuredto” perform a task or operation is particularly structurally formed,constructed, or adapted in a manner corresponding to the task oroperation. For purposes of clarity and the avoidance of doubt, an objectthat is merely capable of being modified to perform the task oroperation is not “configured to” perform the task or operation as usedherein.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the variousembodiments of the disclosure without departing from their scope. Whilethe dimensions and types of materials described herein are intended todefine the parameters of the various embodiments of the disclosure, theembodiments are by no means limiting and are exemplary embodiments. Manyother embodiments will be apparent to those of skill in the art uponreviewing the above description. The scope of the various embodiments ofthe disclosure should, therefore, be determined with reference to theappended claims, along with the full scope of equivalents to which suchclaims are entitled. In the appended claims, the terms “including” and“in which” are used as the plain-English equivalents of the respectiveterms “comprising” and “wherein.” Moreover, the terms “first,” “second,”and “third,” etc. are used merely as labels, and are not intended toimpose numerical requirements on their objects. Further, the limitationsof the following claims are not written in means-plus-function formatand are not intended to be interpreted based on 35 U.S.C. § 112(f),unless and until such claim limitations expressly use the phrase “meansfor” followed by a statement of function void of further structure.

This written description uses examples to disclose the variousembodiments of the disclosure, including the best mode, and also toenable any person skilled in the art to practice the various embodimentsof the disclosure, including making and using any devices or systems andperforming any incorporated methods. The patentable scope of the variousembodiments of the disclosure is defined by the claims, and may includeother examples that occur to those skilled in the art. Such otherexamples are intended to be within the scope of the claims if theexamples have structural elements that do not differ from the literallanguage of the claims, or if the examples include equivalent structuralelements with insubstantial differences from the literal language of theclaims.

What is claimed is:
 1. An adapter assembly of a vehicle, the adapterassembly comprising: a bearing adapter configured to physically contacta bearing on an axle of the vehicle; and an adapter pad nested within anopening of a side frame of the vehicle and secured to at least onethrust lug of the side frame, the adapter pad comprising a base sectionand legs depending from the base section, the legs being compressedbetween the at least one thrust lug of the side frame and shoulders ofthe bearing adapter to exert frictional forces on the shoulders of thebearing adapter, wherein a combination of the frictional forces exertedby the adapter pad on the bearing adapter is less than a weight of thebearing adapter, such that as the side frame rises away from the bearingduring movement of the vehicle, the adapter pad is configured to riserelative to the bearing adapter.
 2. The adapter assembly of claim 1,wherein the base section of the adapter pad is rectangular and theadapter pad has four legs that depend from four corners of the basesection, wherein the legs include ribs projecting from laterally-facingouter surfaces of the legs, and the ribs exert the frictional forces onthe shoulders of the bearing adapter.
 3. The adapter assembly of claim1, wherein the legs include ribs that exert the frictional forces on theshoulders of the bearing adapter, and the ribs project less than 0.08inches from the legs.
 4. The adapter assembly of claim 1, wherein thelegs include ribs that exert the frictional forces on the shoulders ofthe bearing adapter, and the ribs are elongated in a direction that isorthogonal to the force of gravity.
 5. The adapter assembly of claim 1,wherein the legs of the adapter pad include exterior ribs that projectfrom outer surfaces of the legs, and the exterior ribs exert thefrictional forces on the shoulders of the bearing adapter, the adapterpad further including interior ribs that project from inner surfaces ofthe legs, which are opposite the outer surfaces, the interior ribsconfigured to exert frictional forces on the at least one thrust lug tosecure the adapter pad to the side frame via an interference fit.
 6. Theadapter assembly of claim 1, wherein the legs of the adapter pad includeinterior ribs that exert frictional forces on the at least one thrustlug to secure the adapter pad to the side frame via an interference fit.wherein at least one pair of the legs defines a thrust lug cavitybetween the at least one pair, the thrust lug cavity configured toreceive the at least one thrust lug therein, the thrust lug cavity beingsized relative to a width of the at least one thrust lug for theinterior ribs of the legs to grip opposite sides of the at least onethrust lug.
 7. The adapter assembly of claim 1, wherein the adapter padcomprises an elastomeric material, and the bearing adapter comprises ametal material.
 8. The adapter assembly of claim 1, wherein the adapterpad has a durometer hardness in a range from 90A to 58D, and weighs lessthan the bearing adapter.
 9. The adapter assembly of claim 1, wherein asthe side frame rises away from the bearing, the bearing adapter isconfigured to slide along the legs of the adapter pad for the bearingadapter to retain physical contact with the bearing, and the adapter padremains secured to the at least one thrust lug of the side frame.
 10. Atruck assembly of a rail vehicle, the truck assembly comprising: a sideframe that comprises at least one thrust lug; an axle that comprises abearing; and an adapter assembly that comprises an adapter pad and abearing adapter, the adapter pad nested within an opening of the sideframe and secured to the at least one thrust lug via an interferencefit, the adapter pad comprising a base section and legs depending fromthe base section, the bearing adapter comprising multiple shoulders andconfigured to physically contact the bearing, wherein the legs of theadapter pad are compressed between the at least one thrust lug of theside frame and the shoulders of the bearing adapter, the legs includingribs that exert frictional forces on the shoulders, wherein acombination of the frictional forces provided by the ribs is less than aweight of the bearing adapter such that as the side frame rises awayfrom the bearing during movement of the rail vehicle, the adapter pad isconfigured to rise relative to the bearing adapter.
 11. The truckassembly of claim 10, wherein the base section of the adapter pad isrectangular and the adapter pad has four legs that depend from fourcorners of the base section, the ribs projecting from laterally-facingouter surfaces of the legs.
 12. The truck assembly of claim 10, whereinthe ribs project less than 0.08 inches from the legs.
 13. The truckassembly of claim 10, wherein the ribs are longitudinally elongated in adirection that is orthogonal to the force of gravity.
 14. The truckassembly of claim 10, wherein the ribs are exterior ribs, and theadapter pad further comprises interior ribs that project from oppositesides of the legs relative to the exterior ribs, the interior ribsconfigured to exert frictional forces on the at least one thrust lug tosecure the adapter pad to the side frame via the interference fit. 15.The truck assembly of claim 14, wherein at least one pair of the legsdefines a thrust lug cavity configured to receive the at least onethrust lug between the legs in the at least one pair, wherein the thrustlug cavity is sized relative to a width of the at least one thrust lugfor the interior ribs along the legs to grip opposite sides of the atleast one thrust lug.
 16. The truck assembly of claim 10, wherein theadapter pad comprises an elastomeric material.
 17. The truck assembly ofclaim 10, wherein the adapter pad has a durometer hardness in a rangefrom 90A to 58D, and weighs less than the bearing adapter.
 18. The truckassembly of claim 10, wherein as the side frame rises away from thebearing, the bearing adapter is configured to slide along the legs ofthe adapter pad for the bearing adapter to retain physical contact withthe bearing, and the adapter pad remains secured to the at least onethrust lug of the side frame via the interference fit.
 19. A method forforming a truck assembly of a rail vehicle, the method comprising:installing an adapter pad within an opening of a side frame such thatthe adapter pad secures to at least one thrust lug of the side frame viaan interference fit, the adapter pad comprising a base section and legsdepending from the base section; loading a bearing adapter into theopening such that the legs of the adapter pad are compressed byshoulders of the bearing adapter; and coupling the side frame to an axlesuch that an arcuate lower edge of the bearing adapter physicallycontacts a bearing on the axle, wherein the legs exert frictional forceson the shoulders of the bearing adapter, and a combination of thefrictional forces provided by the legs is less than a weight of thebearing adapter such that the bearing adapter lowers relative to theadapter pad, due to the weight, as the side frame rises away from thebearing during movement of the rail vehicle.
 20. The method of claim 19,wherein installing the adapter pad comprises loading the at least onethrust lug into a thrust lug cavity of the adapter pad, the thrust lugcavity defined between the legs of at least one pair of legs of theadapter pad, and loading the bearing adapter into the opening comprisespositioning the bearing adapter such that the legs of the adapter padare sandwiched between the at least one thrust pad and the shoulders ofthe bearing adapter.